Culture
Easily grown in average, medium moisture, well-drained soils in full sun to part shade. Prefers consistent moisture. Adapts to a variety of soils. Species plants will self-seed, but new seedlings are not always true. Self-seeding can occur in optimum conditions. Best propagated from cuttings. Plant 24-30” apart for a hedge that may be pruned to desired height.
Noteworthy Characteristics
Frangula alnus is commonly called alder buckthorn because it is frequently seen in the wild growing in moist soils near alders (genus Alnus). It is also commonly called glossy buckthorn in reference to its glossy leaves. Glossy, oval to obovate, dark green leaves (to 3” long) retain green color well into fall, usually resulting in poor fall color. Insignificant whitish-green flowers appear in axillary clusters in May-June. Flowers are attractive to bees. Flowers are followed by inedible berries that ripen in July. Berries change from green to red to dark purple as they mature. Birds are attracted to the berries and help spread them over the landscape and into neighboring areas. This plant is considered invasive in parts of the Northeast and Midwest regions of the United States. Check local laws before planting this species or any cultivars derived from it. Also consider choosing a native alternative such as common witch hazel (Hamamelis virginiana), blackhaw viburnum (Viburnum prunifolium), or black chokeberry (Aronia melanocarpa).
The genus name Frangula comes from the word "frango", meaning fragile or brittle, in reference to the tendency of the twigs of some species to break easily.
The specific epithet alnus refers to the alder genus Alnus. This plant is often found grown in moist habitats near alders.
‘Columnaris’, also known as tallhedge buckthorn, is a fastigiate, once patented cultivar that was originally grown by the patent holder from seed. It has been popular in commerce since the 1950s. It is a deciduous shrub that typically grows in a narrow fastigiate shape to 12-15’ tall but to only 4’ wide with its stems and branches erect, laterally compact, close together and sometimes twining. U.S. Plant Patent PP1,388 was issued April 26, 1955.
Problems
Japanese beetles, caterpillars and scale may appear. Nematodes can attack the roots. Watch for cankers, leaf spots and rust.
Uses
Hedge (may be pruned back every 1-2 years to maintain 3-4’ tall form). Also excellent privacy screen or narrow accent shrub. Foundations.